Macromolecular antibacterial agent is a functional monomer with antibacterial properties, through grafting, copolymerization and other means to introduce antibacterial functional groups into the long polymer chain, which is to make the polymer itself antibacterial. Due to the fact that some antibacterial agents in China are easy to change color, and the antibacterial functional ions or groups are easy to migrate, the wide application of antibacterial plastics is restricted. In order to solve the existing problems, the patent CN101628952B introduces a preparation method of an antibacterial agent containing guanidine hydrochloride, which is specifically as follows:

1. Synthetic functionalized guanidine salt

Weigh 15 parts of maleic anhydride dissolved in 40 parts of absolute ethanol or acetone to prepare a 27.3% maleic anhydride solution;

Weigh 20 parts of guanidine hydrochloride and dissolve in 40 parts of absolute ethanol or acetone to prepare a 33.3% guanidine hydrochloride solution;

Take the prepared guanidine hydrochloride solution and maleic anhydride solution, mix, stir, add a spherical condenser at the same time, blow in nitrogen for 30 minutes, continue to stir and react in a constant temperature water bath at 50-85℃ for 5-7 hours to obtain a light yellow functionalization Guanidine salt;

(2)Copolymerization of functionalized guanidine salts with monomers with adjustable polarity

Weigh 45 parts of styrene and dissolve in 75 parts of absolute ethanol or toluene to prepare a 37.5% styrene solution;

Weigh 50 parts of acrylamide and dissolve in 75 parts of absolute ethanol or toluene to prepare a 40% acrylamide solution;

Weigh 30 parts of functionalized guanidine salt and dissolve in 75 parts of absolute ethanol or toluene to prepare a 28.6% functionalized guanidine salt solution;

Mix the prepared functionalized guanidine salt solution with styrene solution or acrylamide solution in binary or ternary; blow in nitrogen, add initiator (dicumyl peroxide (DCP) or azobisisobutyronitrile (AIBN) ), the amount of initiator is 2.5 parts), add the solvent for copolymerization (any one of absolute ethanol and toluene), continue to stir in a constant temperature water bath at 70-95℃ for binary or ternary copolymerization, and react for 6-10h , Obtain a milky white viscous liquid; precipitate a white soft white solid that is a guanidine copolymer with a solvent, and dry it in a vacuum drying oven at 60℃ and 0.2MPa for 24 hours to obtain a white blocky guanidine salt copolymerization product, namely guanidine Class polymer type antibacterial agent;

The guanidine polymer type antibacterial agent of the present invention introduces the antibacterial functional group into the long polymer chain by means of copolymerization with the monomer with adjustable polarity, so it has high efficiency, broad spectrum, non-volatile, antibacterial group not easy to migrate, more durable antibacterial function, easy to high temperature processing, good dispersion, easy to store, low price and many other advantages, so there will be a broader prospect.

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